Current authentication systems are threatened by attacks that attempt to determine user passwords, while the corresponding usernames may already be known because usernames are not always considered private information. Moreover, the Advanced Persistent Threat (APT) is currently an issue, and plain-text passwords may be stolen by malware and keylogging software. Some methods to fortify the authentication process include biometrics and one-time passwords, but these techniques may be inaccurate and require specialized devices.